This TMNT mini papercraft is the Leonardo, created by Gus Santome. Leonardo (also named Leo) is a fictional character and one of the four main characters of the Teenage Mutant Ninja Turtles comics and all related media.
In the Mirage comics all four turtles wear red bandanas, but in other versions, he wears a blue bandana. His signature weapons are two ninjaken, which are universally referred to as katana. Throughout the various media he is depicted as the leader of the four turtles and the most disciplined. He is named after Leonardo da Vinci.
You can download this TMNT mini paper craft from here: Teenage Mutant Ninja Turtles (TMNT) - Leonardo Mini Papercraft Download